view mercurial/httppeer.py @ 34679:143337bcec9b

merge: add tests to show current behavior on failed filemerges

Currently, failed file merges will nevertheless force the user to continue
attempting to merge all additional unresolved files. Future patches will allow
the user to halt the merge process instead. This patch first introduces a test
demonstrating the current bejhavior so the upcoming changes are more obvious.

Differential Revision: https://phab.mercurial-scm.org/D930

# httppeer.py - HTTP repository proxy classes for mercurial
#
# Copyright 2005, 2006 Matt Mackall <[e-mail]>
# Copyright 2006 Vadim Gelfer <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

import errno
import io
import os
import socket
import struct
import tempfile

from .i18n import _
from .node import nullid
from . import (
    bundle2,
    error,
    httpconnection,
    pycompat,
    statichttprepo,
    url,
    util,
    wireproto,
)

httplib = util.httplib
urlerr = util.urlerr
urlreq = util.urlreq

def encodevalueinheaders(value, header, limit):
    """Encode a string value into multiple HTTP headers.

    ``value`` will be encoded into 1 or more HTTP headers with the names
    ``header-<N>`` where ``<N>`` is an integer starting at 1. Each header
    name + value will be at most ``limit`` bytes long.

    Returns an iterable of 2-tuples consisting of header names and values.
    """
    fmt = header + '-%s'
    valuelen = limit - len(fmt % '000') - len(': \r\n')
    result = []

    n = 0
    for i in xrange(0, len(value), valuelen):
        n += 1
        result.append((fmt % str(n), value[i:i + valuelen]))

    return result

def _wraphttpresponse(resp):
    """Wrap an HTTPResponse with common error handlers.

    This ensures that any I/O from any consumer raises the appropriate
    error and messaging.
    """
    origread = resp.read

    class readerproxy(resp.__class__):
        def read(self, size=None):
            try:
                return origread(size)
            except httplib.IncompleteRead as e:
                # e.expected is an integer if length known or None otherwise.
                if e.expected:
                    msg = _('HTTP request error (incomplete response; '
                            'expected %d bytes got %d)') % (e.expected,
                                                           len(e.partial))
                else:
                    msg = _('HTTP request error (incomplete response)')

                raise error.PeerTransportError(
                    msg,
                    hint=_('this may be an intermittent network failure; '
                           'if the error persists, consider contacting the '
                           'network or server operator'))
            except httplib.HTTPException as e:
                raise error.PeerTransportError(
                    _('HTTP request error (%s)') % e,
                    hint=_('this may be an intermittent network failure; '
                           'if the error persists, consider contacting the '
                           'network or server operator'))

    resp.__class__ = readerproxy

class _multifile(object):
    def __init__(self, *fileobjs):
        for f in fileobjs:
            if not util.safehasattr(f, 'length'):
                raise ValueError(
                    '_multifile only supports file objects that '
                    'have a length but this one does not:', type(f), f)
        self._fileobjs = fileobjs
        self._index = 0

    @property
    def length(self):
        return sum(f.length for f in self._fileobjs)

    def read(self, amt=None):
        if amt <= 0:
            return ''.join(f.read() for f in self._fileobjs)
        parts = []
        while amt and self._index < len(self._fileobjs):
            parts.append(self._fileobjs[self._index].read(amt))
            got = len(parts[-1])
            if got < amt:
                self._index += 1
            amt -= got
        return ''.join(parts)

    def seek(self, offset, whence=os.SEEK_SET):
        if whence != os.SEEK_SET:
            raise NotImplementedError(
                '_multifile does not support anything other'
                ' than os.SEEK_SET for whence on seek()')
        if offset != 0:
            raise NotImplementedError(
                '_multifile only supports seeking to start, but that '
                'could be fixed if you need it')
        for f in self._fileobjs:
            f.seek(0)
        self._index = 0

class httppeer(wireproto.wirepeer):
    def __init__(self, ui, path):
        self._path = path
        self._caps = None
        self._urlopener = None
        self._requestbuilder = None
        u = util.url(path)
        if u.query or u.fragment:
            raise error.Abort(_('unsupported URL component: "%s"') %
                             (u.query or u.fragment))

        # urllib cannot handle URLs with embedded user or passwd
        self._url, authinfo = u.authinfo()

        self._ui = ui
        ui.debug('using %s\n' % self._url)

        self._urlopener = url.opener(ui, authinfo)
        self._requestbuilder = urlreq.request

    def __del__(self):
        urlopener = getattr(self, '_urlopener', None)
        if urlopener:
            for h in urlopener.handlers:
                h.close()
                getattr(h, "close_all", lambda: None)()

    # Begin of _basepeer interface.

    @util.propertycache
    def ui(self):
        return self._ui

    def url(self):
        return self._path

    def local(self):
        return None

    def peer(self):
        return self

    def canpush(self):
        return True

    def close(self):
        pass

    # End of _basepeer interface.

    # Begin of _basewirepeer interface.

    def capabilities(self):
        if self._caps is None:
            try:
                self._fetchcaps()
            except error.RepoError:
                self._caps = set()
            self.ui.debug('capabilities: %s\n' %
                          (' '.join(self._caps or ['none'])))
        return self._caps

    # End of _basewirepeer interface.

    # look up capabilities only when needed

    def _fetchcaps(self):
        self._caps = set(self._call('capabilities').split())

    def _callstream(self, cmd, _compressible=False, **args):
        if cmd == 'pushkey':
            args['data'] = ''
        data = args.pop('data', None)
        headers = args.pop('headers', {})

        self.ui.debug("sending %s command\n" % cmd)
        q = [('cmd', cmd)]
        headersize = 0
        varyheaders = []
        # Important: don't use self.capable() here or else you end up
        # with infinite recursion when trying to look up capabilities
        # for the first time.
        postargsok = self._caps is not None and 'httppostargs' in self._caps
        if postargsok and args:
            strargs = urlreq.urlencode(sorted(args.items()))
            if not data:
                data = strargs
            else:
                if isinstance(data, basestring):
                    i = io.BytesIO(data)
                    i.length = len(data)
                    data = i
                argsio = io.BytesIO(strargs)
                argsio.length = len(strargs)
                data = _multifile(argsio, data)
            headers['X-HgArgs-Post'] = len(strargs)
        else:
            if len(args) > 0:
                httpheader = self.capable('httpheader')
                if httpheader:
                    headersize = int(httpheader.split(',', 1)[0])
            if headersize > 0:
                # The headers can typically carry more data than the URL.
                encargs = urlreq.urlencode(sorted(args.items()))
                for header, value in encodevalueinheaders(encargs, 'X-HgArg',
                                                          headersize):
                    headers[header] = value
                    varyheaders.append(header)
            else:
                q += sorted(args.items())
        qs = '?%s' % urlreq.urlencode(q)
        cu = "%s%s" % (self._url, qs)
        size = 0
        if util.safehasattr(data, 'length'):
            size = data.length
        elif data is not None:
            size = len(data)
        if size and self.ui.configbool('ui', 'usehttp2'):
            headers['Expect'] = '100-Continue'
            headers['X-HgHttp2'] = '1'
        if data is not None and 'Content-Type' not in headers:
            headers['Content-Type'] = 'application/mercurial-0.1'

        # Tell the server we accept application/mercurial-0.2 and multiple
        # compression formats if the server is capable of emitting those
        # payloads.
        protoparams = []

        mediatypes = set()
        if self._caps is not None:
            mt = self.capable('httpmediatype')
            if mt:
                protoparams.append('0.1')
                mediatypes = set(mt.split(','))

        if '0.2tx' in mediatypes:
            protoparams.append('0.2')

        if '0.2tx' in mediatypes and self.capable('compression'):
            # We /could/ compare supported compression formats and prune
            # non-mutually supported or error if nothing is mutually supported.
            # For now, send the full list to the server and have it error.
            comps = [e.wireprotosupport().name for e in
                     util.compengines.supportedwireengines(util.CLIENTROLE)]
            protoparams.append('comp=%s' % ','.join(comps))

        if protoparams:
            protoheaders = encodevalueinheaders(' '.join(protoparams),
                                                'X-HgProto',
                                                headersize or 1024)
            for header, value in protoheaders:
                headers[header] = value
                varyheaders.append(header)

        if varyheaders:
            headers['Vary'] = ','.join(varyheaders)

        req = self._requestbuilder(cu, data, headers)

        if data is not None:
            self.ui.debug("sending %s bytes\n" % size)
            req.add_unredirected_header('Content-Length', '%d' % size)
        try:
            resp = self._urlopener.open(req)
        except urlerr.httperror as inst:
            if inst.code == 401:
                raise error.Abort(_('authorization failed'))
            raise
        except httplib.HTTPException as inst:
            self.ui.debug('http error while sending %s command\n' % cmd)
            self.ui.traceback()
            raise IOError(None, inst)

        # Insert error handlers for common I/O failures.
        _wraphttpresponse(resp)

        # record the url we got redirected to
        resp_url = resp.geturl()
        if resp_url.endswith(qs):
            resp_url = resp_url[:-len(qs)]
        if self._url.rstrip('/') != resp_url.rstrip('/'):
            if not self.ui.quiet:
                self.ui.warn(_('real URL is %s\n') % resp_url)
        self._url = resp_url
        try:
            proto = resp.getheader('content-type')
        except AttributeError:
            proto = resp.headers.get('content-type', '')

        safeurl = util.hidepassword(self._url)
        if proto.startswith('application/hg-error'):
            raise error.OutOfBandError(resp.read())
        # accept old "text/plain" and "application/hg-changegroup" for now
        if not (proto.startswith('application/mercurial-') or
                (proto.startswith('text/plain')
                 and not resp.headers.get('content-length')) or
                proto.startswith('application/hg-changegroup')):
            self.ui.debug("requested URL: '%s'\n" % util.hidepassword(cu))
            raise error.RepoError(
                _("'%s' does not appear to be an hg repository:\n"
                  "---%%<--- (%s)\n%s\n---%%<---\n")
                % (safeurl, proto or 'no content-type', resp.read(1024)))

        if proto.startswith('application/mercurial-'):
            try:
                version = proto.split('-', 1)[1]
                version_info = tuple([int(n) for n in version.split('.')])
            except ValueError:
                raise error.RepoError(_("'%s' sent a broken Content-Type "
                                        "header (%s)") % (safeurl, proto))

            # TODO consider switching to a decompression reader that uses
            # generators.
            if version_info == (0, 1):
                if _compressible:
                    return util.compengines['zlib'].decompressorreader(resp)
                return resp
            elif version_info == (0, 2):
                # application/mercurial-0.2 always identifies the compression
                # engine in the payload header.
                elen = struct.unpack('B', resp.read(1))[0]
                ename = resp.read(elen)
                engine = util.compengines.forwiretype(ename)
                return engine.decompressorreader(resp)
            else:
                raise error.RepoError(_("'%s' uses newer protocol %s") %
                                      (safeurl, version))

        if _compressible:
            return util.compengines['zlib'].decompressorreader(resp)

        return resp

    def _call(self, cmd, **args):
        fp = self._callstream(cmd, **args)
        try:
            return fp.read()
        finally:
            # if using keepalive, allow connection to be reused
            fp.close()

    def _callpush(self, cmd, cg, **args):
        # have to stream bundle to a temp file because we do not have
        # http 1.1 chunked transfer.

        types = self.capable('unbundle')
        try:
            types = types.split(',')
        except AttributeError:
            # servers older than d1b16a746db6 will send 'unbundle' as a
            # boolean capability. They only support headerless/uncompressed
            # bundles.
            types = [""]
        for x in types:
            if x in bundle2.bundletypes:
                type = x
                break

        tempname = bundle2.writebundle(self.ui, cg, None, type)
        fp = httpconnection.httpsendfile(self.ui, tempname, "rb")
        headers = {'Content-Type': 'application/mercurial-0.1'}

        try:
            r = self._call(cmd, data=fp, headers=headers, **args)
            vals = r.split('\n', 1)
            if len(vals) < 2:
                raise error.ResponseError(_("unexpected response:"), r)
            return vals
        except socket.error as err:
            if err.args[0] in (errno.ECONNRESET, errno.EPIPE):
                raise error.Abort(_('push failed: %s') % err.args[1])
            raise error.Abort(err.args[1])
        finally:
            fp.close()
            os.unlink(tempname)

    def _calltwowaystream(self, cmd, fp, **args):
        fh = None
        fp_ = None
        filename = None
        try:
            # dump bundle to disk
            fd, filename = tempfile.mkstemp(prefix="hg-bundle-", suffix=".hg")
            fh = os.fdopen(fd, pycompat.sysstr("wb"))
            d = fp.read(4096)
            while d:
                fh.write(d)
                d = fp.read(4096)
            fh.close()
            # start http push
            fp_ = httpconnection.httpsendfile(self.ui, filename, "rb")
            headers = {'Content-Type': 'application/mercurial-0.1'}
            return self._callstream(cmd, data=fp_, headers=headers, **args)
        finally:
            if fp_ is not None:
                fp_.close()
            if fh is not None:
                fh.close()
                os.unlink(filename)

    def _callcompressable(self, cmd, **args):
        return self._callstream(cmd, _compressible=True, **args)

    def _abort(self, exception):
        raise exception

class httpspeer(httppeer):
    def __init__(self, ui, path):
        if not url.has_https:
            raise error.Abort(_('Python support for SSL and HTTPS '
                               'is not installed'))
        httppeer.__init__(self, ui, path)

def instance(ui, path, create):
    if create:
        raise error.Abort(_('cannot create new http repository'))
    try:
        if path.startswith('https:'):
            inst = httpspeer(ui, path)
        else:
            inst = httppeer(ui, path)
        try:
            # Try to do useful work when checking compatibility.
            # Usually saves a roundtrip since we want the caps anyway.
            inst._fetchcaps()
        except error.RepoError:
            # No luck, try older compatibility check.
            inst.between([(nullid, nullid)])
        return inst
    except error.RepoError as httpexception:
        try:
            r = statichttprepo.instance(ui, "static-" + path, create)
            ui.note(_('(falling back to static-http)\n'))
            return r
        except error.RepoError:
            raise httpexception # use the original http RepoError instead